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.(No Model.)

G. P. HELFRIS'H.

v MANUFACTURE OF PAPER PLAQUBS. No. 255,168. 4 Patented Mar. 21,1882.

N. PETERS. Phulo-Llthognpher. washingwn. n.c.

UNITED STATES PATENT OFF C -GEOBGE P. HELFRISH,-OF BOSTON, MASSACHUSETTS, ASSIGNOR TO LOUIS 4 PRANG, OF SAME PLACE.

MANUFACTURE OF PAPER P'LAQUES.

SPECIFIGATIQN forming part of Letters Patent No. 255,168, dated March 21, 1882.

' Application filed November fll, 1881. (No model.)

To all whom it may concern Be it knownthat I, GEORGE P. HELFRISH, of Boston, of the county of Suffolk and State ofMassachusetts, have invented a new and use- 5 fulImprovemen-t'in the Manufacture of Plaques of Paper; and I do hereby declare the same to be described in the following specification and represented inFigures 1 and 2 of the accompanying drawings, which are'transverse sections of such a plaque made in accordance with my invention, the nature of which is defined in the claims hereinafter made.

' The invention specially relates to the manufacture of plaques made of paper or papier- 1'5 mach, which in drying, as well asaftcrward, are very liable to become warped, the object of the invention being not only to strengthen them, but to cause them to retain their proper 7 forms while in the process of manuacture and drying, as well as subsequently. y In carrying out the invention I combine with the wet or moist paper orplastic papier-mach bodyof'the plaque a thin metallic-re-enforcing disk or plate, to be inserted within the said body while it. is wet or moist and before it is pressed into its concavo convex form by dies, the re enforcing plate being thoroughly cov cred on its opposite surfaces and on or about its edges by the wet paper or papier-mach; Having thus properly covered the re-enforcing plate, as described,the whole is to be placed between dies and pressed by them into the reqnisite concavo-convex form, the combined reenforce and body material being subsequently 5 subjected to heat or other suitable means of evaporating the water or moisture. \Vhen wet paper is used it is well to cover the surfaces with paste, glue, or cement of some suitable kind,in order to effect not onlya strong ad hesion of the layers ofpaper to each other, but to the re-enforce. The body materialis usually made of layers of paper laid on each other on each side of the re-enforce, the pack on one side of it extending beyond it and lapping for a short distance on the pack on the other side; or the article may consist of two layersor disks of pasteboard and the re-enforcingplate body material, the i e-enforcing plate is perfobetween them, in which case, as well as when papier-mach or sheets of paper constitute the rated or made foraminous, in order that the material on either side of it may be pressed into and through the re-enforce, so as to come 7 into close contact with or unite with the material on the opposite side of such re-ent'orce.

In the drawings, Figures 1 and 2 represent the paper plaque in its transverse section, the re-enforce being shown in Fig. 2 as perforated or foraininous. In some cases it may be a woven wire or meshed fabric. In each of these figures the body material is shown at A and the metallic re-enforce at B.

By first applying the bodymaterial to the reenforce in a flat state and neXt reducing both to a concavo-convex form by-dies the paper and re-enforce become simultaneously expanded and reduced to shape and combined, and the water is expelled to much better advautage then follows from first reducing by dies the re-enforce to form and next applying the paper to it; and, besides, the paper may be applied in the form of pasteboard, which it cannot be when the re-enforce is concavo-convex, as the dies would cause, in mostif not all cases, overstraining and rupture of the board.

I therefore claim--- 7 1. As a new orimprovedarticle of manufacture,'a plaque having a body consisting of paper or pasteboard, and'a rc-enforcing plate of metal, arranged therein and completely co\'-- ered thereby, and both rendered concavo-conve'X simultaneously between and by dies, as set forth. a

2. As an improved article of manufacture, a plaque composed of layers of paper or paste- 85 board and a foraminous or perforated metallic plate or meshed re-ent'orce, arranged as de scribed, and rendered simultaneously cone-avoconvex and smoothed by means of dies, as set forth.

GEORGE P. HELFRISH. Witnesses: v

R. H. EDDY,

E. B. PRATT. 

